1. Field of the Invention
The present invention relates to a composite lathe including: a first and a second spindle headstock disposed on a bed; a tool post disposed between the first and second spindle headstocks; and a third spindle disposed on the bed to be movable in X-axis, Y-axis, and Z-axis directions.
2. Description of the Related Art
An example of a composite lathe of this type is structured such that a is spindle headstock is fixedly disposed on one end of a bed and a lower tool post and an upper tool post are disposed on a lower side and an upper side of a tool post supporting part in a slanted shape respectively to be movable in an X-axis and a Z-axis direction (see, for example, Patent document 1).
[Patent document 1] Japanese Patent Application Laid-open No. Hei 6-106438
Incidentally, the aforesaid conventional composite lathe has a problem that the front/back direction dimension of the machine main body increases since the lower tool post is disposed on an outer side in the machine front/back direction than a vertical line going through an axis of the spindle headstock.
Further, the structure in which the upper tool post and the lower tool post are moved on the same plane has a problem that machining areas of the both tool posts are limited.